Process and apparatus for the manufacture of artificial silk and other artificial textile products from cellulose solutions by the dry or evaporative method



June 5, 1928. 1,672,665

S. l. VLES ET AL PROCESS AND APPARATUS FOR THE MANUFACTURE OF ARTIFICIAL' SILK AND OTHER ARTIFICIAL TEXTILE PRODUCTS FROM CELLULOSE SOLUTIONS BY THE DRY OR EVAPORATIVE METHOD Filed Feb. 10, 1927 Jamil/H2233.

Patented June 5, 1928.

UNITED STATES .HETHERLANDS, ASSIGNORS TO SAMUEL ISIDOORVLES AND MARTINUS PETRUS ANTONIUS BOUMAN, OF ARNHEM, A

NAAMLOOZE VENOOTSCHAP NEDERLANDSCHE 'KUNSTZIJDEFABRIEH. OF ARNHEM. NETHERLANDS.

PROCESS AND APPARATUS FOR THE MANUFACTURE OF ARTIFICIAL SILK AND OTHER ARTIFICIAL TEXTILE PRODUC'I'SFROM CELLUL-OSE SOLUTIONS BY THE DRY OR EVAPORATIVE METHOD.

Application filed February 10, 1927, Serial No. 167,194; and in the Netherlands December 17, 1926.

()ur invention relates to a process and apparatus for the manufacture of artificial silk and other artificial textile products from cellulose solutions by the dry or evaporw tive method.

The term "cellulose solutions" whenever used in this specification and the claims is intended to cover solutions of cellulose compounds, such as cellulose nitrate, cellulose acetate, alkyl, aryl, and aralkyl cellulose and other mixed or single esters and ethers of cellulose, in ether, acetone, alcohol-ether,

and other volatile solvents, ormixtures ol" solvents, such as are used for the manufacture of artificial silk and other artificial textile products.

In the manufacture of artificial silk from solutions of the kindreferred to with the aid of the so called .dry or evaporative method the solutions were, generally, caused to extrude through fine openings ororifices into a heated atmosphere, so that owing to the evaporation of the volatile solvent the cellulose compound was solidified. Al-

though it has been proposed already to carry out the spinning in an upward direction. generally the opposite way was adopted. This spinning downwards has been carried out always in a closed casing, this being considered necessary in order to prevent turbulent movement and to recover the solvent.

Generally the air in the casing was heated, for instance by arranging heating spirals in the lower part of the casing or metiel'x The heated air ascended'and was removed, together with the vapours of the volatile solvent, in the uppermost part of the casing. Further it. has been proposed to apply no heating in the casing and to carry out the 60 Winding of the spun material in a second,

separate casing, this second casing being heated and serving for further leading off the evaporated solvent to a regenerative apparatus for this solvent.

Further it is known to lead into or to circulate in the closed spinning metier a stream of gas consisting of air containing a considerable amount of the volatile solvent, in order to make the cross section of the thread more uniform.

The volatile solvents being rather costly it is obvious that much attention was paid to the'recovery of the solvent. and that a closed casing was considered to be a necessary condition and more specially as the closed casing was intended to prevent turbulent motion in the heated or not heated gaseous medium, which causes a very detrimental effect on the spinning process. Also a complete, uniform cr'osssection of the thread is a veryimportant conditionin spinning artificial silk, and more attention was paid laterally to this. i

However, the proposals in this respect show several drawbacks. Thus spinning in a cold, not heated atmosphere requires a separate, second casing, which makes the handling of the wholeapparatus only more difficult. This drawback also adheres to the proposal to carry out the spinning in an atmosphere containing vapours of the solvent; finally the closed casing, even if provided at the lower part. with a funnel shaped piece, polished at the inner side, does not facilitate the handling.

These drawbacks are removed. by applying our present invention, several advantages being obtained which will be described in the following part of the specification.

The process according to our invention shows the characteristic that the cellulose solutions are extruded through fine appertures in a downward direction into a slowly ascendingmedium, whose temperature increases gradually in an upward direction.

The process according to'our invention may be carried out also in a casing which is open at. the lower part thereof.

According to our invention the slow' as rent of the medium in the casing is preferably regulated or controlled by means of an outlet arranged at the upper part of the casing. V

Further our invention comprises an apparatus for carrying out the novel process consisting in a vertical or practically vertical casing which is wholly or practically whooly surrounded by heating means, and which contains an outlet at the upper part in proximity to the outlet openings for the cellulose solution. I

According to our invention, the casing is preferably open at the bottom.

By causing the medium into whichthe cel lulose solution is extruded in a downward spinning process.

direction to ascend slowly and by causing the temperature of the ascending medium to increase gradually, and by a suitable regulation of the outflow of the atmosphere containing vapours of the solvent, we practically eliminate turbulent motion, which latter can efi'ecta very unfavourable influence on the Moreover, the great advantage is obtained that the evaporation of the solvent takes place in an atmosphere containing a s'uflicient quantity of the solvent,

this being-as is known--of considerable advantage for the product to be obtained. According to our invention this favourable result is obtained without complicated arrangements such as have been proposed for this purpose. x

In" using a casing open at the lower Side no losses of the solvent will occur if the regulation of the temperature and the velocity of the outlet of the vapours is carried out in a suitable way; further the casing is easily accessible. instance it is desirable to maintain the temperature outside the casing, at any rate in the proximity of the open lower part thereof, somewhat lower than the lowest temperature in the casing.

In order to elucidate our invention an embodiment of the process and the apparatus will be described with reference to the annexed, diagrammatic drawing.

1 is a vertical metal casing of about 2 metres length and a cross section of about 25 centimetres. This casing 1 has 'at the upper part an opening through which leads a. supply pipe 2 for the spinning solution. In this supply pipe 2 a known spinning pump 3 is arranged, which leads the spinning solution with controllable velocity through the pipe 2 to the spinning nozzle 4. Through fine apertures in the spinning nozzle 4 the spinning liquid leaves the spinneret 4 and descends through the slowly ascending atmosphere in-the casing 1; the spun material 5 is wound up by winding device 6 and may be twisted at once. If desired the spun material 5 may be led away by means of a guide 7..

Around the casing 1 is arranged a jacket 8 in which circulates a liquid or other heating medium entering at 9, and flowing off at 10. By regulating the temperature of this heating medium in connection with its velocity a temperature gradually decreasing from the top in a downward direction is obtained.

In spinning a solution of cellulose acetate in acetone .a suitable range of the temperature is for instance that at the upper part of the casing a temperature of about 50 and at the lower part of the casing a temperature of about 20 C. prevails.

It is obvious that in thispipe 11 and suction device 12. This pipe 11 leads to an apparatus (not shown) for the recovery of the solvent.

Our invention in the first place provides a simple apparatus which is easy to handle and easily accessible. In the second place it is possible to wind up in a place perpendicular beneath the spinneret, a moving thread guide being even superfluous, this forming a further advantage of our invention.

\Vhen we refer to a casing open at its lower end we mean a casing having a large hole at its lower end, as distinct from an orifice e. g. a casing having the form of an inverted closed cylinder.

We claim:

1. Process of manufacturing, artificial silk and other artificial textile products from cellulose solutions according to the dry or evaporative method in which the cellulose solutions are extruded through fine apertures into a. slowly ascending medium the temperature of which increases gradually in an upward direction.

2. Process of manufacturing artificial silk and other artificial textile products from cellulose solutions according to the dry or evaporative method by using a casing open at the bottom and in which the cellulose solutions are extruded through fine apertures into a slowly ascending medium the temperature of which increases gradually in an upward direction.

3. Process of manufacturing artificial silk and other artificial textile products from cellulose solutions according to the dry or evaporative method in which the cellulose solutions are extruded through fine apertures into a slowly ascending medium the temperature of which increases gradually an upward direction in which the rate of ascent of the medium in the casing is controlled or regulated by an outlet arranged at the top of the casing.-

5. Apparatus for carrying out the process of manufacturing artificial silk and other artificial textile products from cellulose solutions according to the dry or evaporative method consisting in a practically vertical casing which is at least for the greater part of its length and particularly toward its upper end, surrounded by a heating means the temperature of which increases from the bottom to the top, the casing having an outlet for the ascending medium provided with a regulating or controlling means and in proximity to the apertures for the cellulose solution.

6. An apparatus for carrying out the process of manufacturing artificial silk and other artificial textile products from cellulose solutions according to the dry or evaporated method consisting in a' practically vertical casing which is at least for the greater part surrounded by a heating jacket having an inlet at the top and an outlet "-near the bottom, the casing having an outlet for the ascending medium provided with a regulating or controlling means and method; consisting in a practically vertical v casing which is for the greater part at least surrounded by a heating jacket having an inlet at the top end and an outlet near the bottom end, the casing having an outlet for the ascending medium provided with a regulating or controlling means and in proximity to the apertures for the cellulose solution and being open at its bottom end.-

In testimony whereof we affix our signatures'.

SAMUEL lSlDOOR VLES. MARTtNUS PETRUS ANTONlUS BOUMAN. 

